How to Boil a Nucleus

The intense heat and pressure of a supernova causes stellar matter to undergo a phase transition, condensing from a gas into nuclear "liquid" as it forms a neutron star or black hole. Although this super-dense material is impossible to study first hand, the nuclei of heavy elements on earth approach its density and share its fluid properties. Recent experiments that collide particles with atomic nuclei indicate that it is possible to "boil" an atomic nucleus to better understand the characteristics of nuclear liquid. Based on analysis of the fragments ejected from the bombardment, the authors offer evidence not only of a vaporization phenomenon but also for a dramatic expansion of the nucleus following the collision.